1,997 research outputs found
On the Core of Dynamic Cooperative Games
We consider dynamic cooperative games, where the worth of coalitions varies
over time according to the history of allocations. When defining the core of a
dynamic game, we allow the possibility for coalitions to deviate at any time
and thereby to give rise to a new environment. A coalition that considers a
deviation needs to take the consequences into account because from the
deviation point on, the game is no longer played with the original set of
players. The deviating coalition becomes the new grand coalition which, in
turn, induces a new dynamic game. The stage games of the new dynamical game
depend on all previous allocation including those that have materialized from
the deviating time on.
We define three types of core solutions: fair core, stable core and credible
core. We characterize the first two in case where the instantaneous game
depends on the last allocation (rather than on the whole history of
allocations) and the third in the general case. The analysis and the results
resembles to a great extent the theory of non-cooperative dynamic games.Comment: 25 page
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Visual analysis design to support research into movement and use of space in Tallinn: A case study
We designed and applied interactive visualisation to help an urban study group investigate how suburban residents in the Tallinn Metropolitan Area (Estonia) use space in the city. We used mobile phone positioning data collected from suburban residents together with their socio-economic characteristics. Land-use data provided geo-context that helped characterise visited locations by suburban residents. Our interactive visualisation design was informed by a set of research questions framed as identification, localisation and comparison tasks. The resulting prototype offers five linked and coordinated views of spatial, temporal, socio-economic characteristics and land-use aspects of data. Brushing, sorting and filtering provide visual means to identify similarities between individuals and facilitate the identification, localisation and comparison of patterns of use of urban space. The urban study group was able to use the prototype to explore their data and address their research questions in a more flexible way than previously possible. Initial feedback was positive. The prototype was found to support the research and facilitate the discovery of patterns and relations among groups of participants and their movements
Economic nationalism and the cultural politics of consumption under austerity: the rise of ethnocentric consumption in Greece
By nuancing the politics of consumption in the context of austerity, this article highlights the rise of economic nationalism and the reconfiguration of consumer cultures at the aftermath of the global financial crisis. As it argues, in the context of Greece, three types of consumer culture have manifested; these are evoking consumption as resilience, resistance or reinforcement. This work focuses on the latter through the phenomenon of ethnocentric consumption, which is part and parcel of economic nationalism. Economic nationalism can be explored through promotion of ethnocentric consumption and is demonstrable both in the inception and constitution of nation states, but also in times of crisis. This article critically appraises ethnocentric consumption as consumption based on ethnocentric criteria (natural resources, ownership, production, manufacturing, distribution and labour force). In the context of the crisis in Greece, economic nationalism has become manifest as a solution to the national economy. The specific case chosen is a citizens’ movement and its campaign for the promotion of ethnocentric consumption. A close examination of the campaign (We Consume What We Produce) reveals the historical alignment of the state’s and citizens’ economic interests, the reverberation of state narrative from the 1980s and exclusionary nationalism which is also used by fascists. Campaigns for ethnocentric consumption limit the creativity of consumer politics. First, this phenomena appears to be an alternative vehicle for political parties. Second, it is tied around a normative narrative of economic recovery, which is particularly mythological. Third, its overall target is to maximise competitiveness on a global scale, and finally, it demonstrates a densely dangerous relationship with economic nationalism. Yet, it is important to situate this phenomenon within the context of consumer cultures under austerity, especially as more creative modalities of social economy initiatives by grassroots groups have been re-socialising the market
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Probing the metallicity and ionization state of the circumgalactic medium at z ~ 6 and beyond with OI absorption
Low ionization metal absorption due to OI has been identified as an important
probe of the physical state of the inter-/circumgalactic medium at the tail-end
of reionization. We use here high-resolution hydrodynamic simulations to
interpret the incidence rate of OI absorbers at z~6 as observed by Becker et
al. (2011). We infer weak OI absorbers (EW > 0.1 A) to have typical HI column
densities in the range of sub-DLAs, densities of 80 times the mean baryonic
density and metallicities of about 1/500 th solar. This is similar to the
metallicity inferred at similar overdensities at z~3, suggesting that the metal
enrichment of the circumgalactic medium around low-mass galaxies has already
progressed considerably by z~6. The apparently rapid evolution of the incidence
rates for OI absorption over the redshift range 5<z<6 mirrors that of
self-shielded Lyman-Limit systems at lower redshift and is mainly due to the
rapid decrease of the meta-galactic photo-ionization rate at z>5. We predict
the incidence rate of OI absorbers to continue to rise rapidly with increasing
redshift as the IGM becomes more neutral. If the distribution of metals extends
to lower density regions, OI absorbers will allow the metal enrichment of the
increasingly neutral filamentary structures of the cosmic web to be probed
Discovery of a single male Aedes aegypti (L.) in Merseyside, England
© The Author(s). 2017. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. The file attached is the published (publishers PDF) version of the article
Climate Dynamics: A Network-Based Approach for the Analysis of Global Precipitation
Precipitation is one of the most important meteorological variables for defining the climate dynamics, but the spatial patterns of precipitation have not been fully investigated yet. The complex network theory, which provides a robust tool to investigate the statistical interdependence of many interacting elements, is used here to analyze the spatial dynamics of annual precipitation over seventy years (1941-2010). The precipitation network is built associating a node to a geographical region, which has a temporal distribution of precipitation, and identifying possible links among nodes through the correlation function. The precipitation network reveals significant spatial variability with barely connected regions, as Eastern China and Japan, and highly connected regions, such as the African Sahel, Eastern Australia and, to a lesser extent, Northern Europe. Sahel and Eastern Australia are remarkably dry regions, where low amounts of rainfall are uniformly distributed on continental scales and small-scale extreme events are rare. As a consequence, the precipitation gradient is low, making these regions well connected on a large spatial scale. On the contrary, the Asiatic South-East is often reached by extreme events such as monsoons, tropical cyclones and heat waves, which can all contribute to reduce the correlation to the short-range scale only. Some patterns emerging between mid-latitude and tropical regions suggest a possible impact of the propagation of planetary waves on precipitation at a global scale. Other links can be qualitatively associated to the atmospheric and oceanic circulation. To analyze the sensitivity of the network to the physical closeness of the nodes, short-term connections are broken. The African Sahel, Eastern Australia and Northern Europe regions again appear as the supernodes of the network, confirming furthermore their long-range connection structure. Almost all North-American and Asian nodes vanish, revealing that extreme events can enhance high precipitation gradients, leading to a systematic absence of long-range patterns
Oncogenic and incidental HPV types associated with histologically confirmed cervical intraepithelial neoplasia in HIV-positive and HIV-negative South African women
Background. In Africa, data on the relationship between oncogenic human papillomavirus (HPV) types, immune status and cervical preinvasive lesions are lacking.Methods. We investigated low-risk (lrHPV) and high-risk (hrHPV) HPV types in a cohort of women with cervical intraepithelial neoplasia (CIN) II/III confirmed on histological examination, in an urban setting with a high prevalence of HIV infection.Results. Of 270 women with confirmed CIN II/III, 45 were HIV-negative and 225 HIV-positive. HIV-infected women had significantly more HPV type infections, including all HPV (p<0.001) and hrHPV (p=0.014) types. The prevalences of one or more hrHPV type/s were 93.3% and 92.9% in HIV-negative and positive patients, respectively. The most prevalent hrHPV type among HIV-negative women was HPV 16, followed by HPV 52, 31, 35 and 58. Among HIV-positive women, HPV 16 was followed by HPV 58, 35, 51 and 52. Not yet qualifying for highly active antiretroviral therapy (HAART) (CD4 count >350 cells/μL) or having received HAART for ≥12 months were negatively associated with HPV 18, 33, 45, 51, 52, 59 and 82.Conclusions. In South Africa, burdened by the HIV pandemic, high numbers of high- and low-risk HPV type infections are present in women with cervical preneoplasia. HPV type distribution differs among varying levels of HIV-induced immune depletion
Disguised Propaganda from Digital to Social Media
Disguised propaganda and political deception in digital media have been studied since the early days of the World Wide Web. At the intersection of internet research and propaganda studies, this chapter explores disguised propaganda on websites and social media platforms. Based on a discussion of key concepts and terminology, this chapter outlines how new modes of deception and source obfuscation emerge in digital and social media environments, and how this development complicates existing conceptual and epistemological frameworks in propaganda studies. The chapter concludes by arguing that contemporary challenges of detecting and countering disguised propaganda can only be resolved, if social media companies are held accountable and provide the necessary support for user contestation
A programme theory for liaison mental health services in England
Background:
Mechanisms by which liaison mental health services (LMHS) may bring about improved patient and organisational outcomes are poorly understood. A small number of logic models have been developed, but they fail to capture the complexity of clinical practice.
Method:
We synthesised data from a variety of sources including a large national survey, 73 in-depth interviews with acute and liaison staff working in hospitals with different types of liaison mental health services, and relevant local, national and international literature. We generated logic models for two common performance indicators used to assess organisational outcomes for LMHS: response times in the emergency department and hospital length of stay for people with mental health problems.
Results:
We identified 8 areas of complexity that influence performance, and 6 trade-offs which drove the models in different directions depending upon the balance of the trade-off. The logic models we developed could only be captured by consideration of more than one pass through the system, the complexity in which they operated, and the trade-offs that occurred.
Conclusions:
Our findings are important for commissioners of liaison services. Reliance on simple target setting may result in services that are unbalanced and not patient-centred. Targets need to be reviewed on a regular basis, together with other data that reflect the wider impact of the service, and any external changes in the system that affect the performance of LMHS, which are beyond their control
Aneuploidy in pluripotent stem cells and implications for cancerous transformation
Owing to a unique set of attributes, human pluripotent stem cells (hPSCs) have emerged as a promising cell source for regenerative medicine, disease modeling and drug discovery. Assurance of genetic stability over long term maintenance of hPSCs is pivotal in this endeavor, but hPSCs can adapt to life in culture by acquiring non-random genetic changes that render them more robust and easier to grow. In separate studies between 12.5% and 34% of hPSC lines were found to acquire chromosome abnormalities over time, with the incidence increasing with passage number. The predominant genetic changes found in hPSC lines involve changes in chromosome number and structure (particularly of chromosomes 1, 12, 17 and 20), reminiscent of the changes observed in cancer cells. In this review, we summarize current knowledge on the causes and consequences of aneuploidy in hPSCs and highlight the potential links with genetic changes observed in human cancers and early embryos. We point to the need for comprehensive characterization of mechanisms underpinning both the acquisition of chromosomal abnormalities and selection pressures, which allow mutations to persist in hPSC cultures. Elucidation of these mechanisms will help to design culture conditions that minimize the appearance of aneuploid hPSCs. Moreover, aneuploidy in hPSCs may provide a unique platform to analyse the driving forces behind the genome evolution that may eventually lead to cancerous transformation
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